Drafting board



y 4, 1954 R. c. BERGER 2,677,185

DRAFTING BOARD Filed Feb. 29, 1952 2 Sheets-Sheet 1 May 4; 1954 R. c. BERGER 2,677,185

DRAFTING BOARD 2 Sheets-Sheet 2 Filed Feb. 29, 1952 FIG. /0.

Patented May 4, 1954 UNITED STATES PATENT OFFICE DRAFTING BOARD Robert C. Berger, Raleigh, N. 0.

Application February 29, 1952, Serial No. 274,182

6 Claims.

This invention relates generally to improvements in drawing boards, and is particularly directed to improvements in drawing boards of the roller and endless web type.

It is a principal object of the present invention to provide a drawing board of the type described which will enable the draftsman to work on and reach easily any part of the drawing through the automatic and continuous movement of the drawing itself. lead and control this movement while drawing as usual with the straight-edge rule by means of the same straight-edge rule. Other objects of the invention will be appreciated by those skilled in the art, upon reading and understanding the following specification. This-invention will be fully and clearly understood from a consideration of the following detailed description when read in connection with the accompanying drawings, which form part of the application, with the understanding however that this invention is capable of extended applications and is not confined to the exact showing of the drawings, nor to the precise construction described, andtherefore, such changes and modifications may be made therefrom as do not affect the spirit of the invention, nor exceed the scope thereof as expressed in the appended claims.

In the drawings:

Fig. 1 is a diagrammatic view illustrating the operating principles of my drafting board.

Fig. 2 is a perspective view of my drafting board embodying the principle shown on Fig. l, and partly broken away for clarity of understanding.

Fig. 3 is an exploded, fragmentary view of my drafting board shown in Fig. 2.

Fig. 4 is a side elevational view of the same board, partly broken away to conserve space.

Fig. 5 is a partial, transverse sectional view taken through the rear roller of the drawing board.

Fig. 6 is a partial, longitudinal sectional view also taken through the rear roller of the device.

Fig. '7 is a partial, side elevational view showing one form of connection adapted to be employed between the straight edge rule and the the form of connection illustrated in Fig. 7.

Fig. 9 is a partial, transverse sectional view taken through the front roller of the drawing board device.

. Fig. 10 is a partial, longitudinal sectional view also taken through the front roller of the device.

The draftsman will determine,-

iii)

All these figures refer to an example of the simplest type of drafting board built according to the principle illustrated in Fig. 1. The name of drafting board as used in the description and claims, or any indication given in the drawings concerning the materials of which every part of the drafting board may be made, are not confined to any certain material but include any and all suitable materials which may be employed to advantage.

Description of Fig. 1:

The geometrical explanation of the operating principles of the present invention are illustrated in Fig. 1, where a surface or area I is generated by the line 2 moving parallel to itself in arcuate, or semi-cylindrical paths about the center points 3 and 4, and in substantially parallel spaced upper and lower planes or stretches extending between and tangent to the arcuate surfaces or areas.

Let us build a rectangular frame the plane of which will contain line 2 and will be perpendicular to the area I, the line 2 being the long side of the frame. The short side 6 is longer than the diameter of the circles described by the area around the points 3 and 4. This means that the long side 1 opposite to the line 2 is outside of the upper stretch of the area I. Let us move the frame in the direction shown by the arrows. While in motion the frame is kept perpendicular and attached to the area I by its side 2. The area I will move as the arrows show while the long side I of the frame will move in the opposite direction. The successive projections of the side I on the area I namely la, lb, 1c, etc. will be parallel to each other. This means that a straight-edge rul replacing side 1 may serve to trace on the area I parallel lines such as 1a., lb, 'Ic, etc. The consequences of the arrangement described above are the following; v

If a force 3 is applied to the Side 1 ofv the frame as shown this force will determine the motion of both the frame and the area I. The upper stretch of the area I will move in a direction opposite to that of the side 1 of the frame. This means that a point 9 on the area I will come toward the side I, while in the same time and with an equal speed the line 'i will approach the new position of the point 9, 911 until the projection 1d of the line i will meet 9a halfway between the initial positions of the side 'i and the point 9. Practically this means that a straight-edge rule replacing the side 1 will move on the board twice as fast as a usual T-square for the draft of all horizontal'lines of a drawing fixed to my drafting board.

The force 8 sets in movement the whole system, controls its speed and can stop it as desired. It can be applied also in the direction opposite to that shown, reversing the movement of the Whole system. Practically this means that any part of a drawing drawn on the area I can be brought closer or farther from the draftsman who is working on one side of the area I by acting on the straight-edge rule which replaces the side I of the frame. The draftsm'an controls the speed of the movement of the area I and can stop the whole system as he desires. He also can bring at any moment any part, or the entire drawing on the upper stretch or side of the area I where it becomes visible for reference, redrawing and modification. While giving to the area I the motion described above, the draftsman uses his straight edge rule as he does the T-square on an ordinary board. p

Description of Figures 2 to In Figures 2 to 10, I show a drafting board embodying the principle described above.

The area i is embodied in my drafting board by an endless web on which one can draw directly or can use it as a base to which drawing paper may be attached by means of Scotch tape. This web area I is stretched by means of rollers 3 and 4 upon a backing plate or supporting board I3 which is provided under the upper stretch of the web and fixed at the top side of a frame supporting all the component parts of the system. In the front and the rear of this drafting board, parallel to each other, are mounted to the same frame two'rollers' 3- and 4 around which the web is stretched. These rollers have a smooth surface. One of them 3 is mounted directly in front of the supporting board. The second, number 4,

in the rear of the'supporting board is mounted on an adjustable device which permits the motion of the roller toward or away from the rear edge of the support board enough to keep the endless web stretched for a good support area on the drafting board. Both rollers can be mounted into the frame on their simple axis or on ball-bearings. Fixed on to the lower web stretch below the supporting board is a rule 2 parallel to both rollers. This rule has its ends sliding in an elongated, narrow slit I4 in each of the side members of the frame and extending beyond the said sides of the frame. In order to allow the rule to slide more smoothly in the slits, two round-headed nails I? are fixed into each of its ends. The rule is fixed to the web by devices as simple as thumbtacks It on more complicated such as screws, springs or others. rollers on track-rails mounted in the slits I4, or he slid on edge ball-bearings mounted in the same fashion. Such improvementsprovide more expensive types of the same invention. If for any reason it is desirable to convert my drafting board into a conventional static board, means are provided to that effect, immobilizing the web in the desired position. At two end positions and a middle one along the slit I4 on both sides of the frame stopping devices are provided. The devices consist of an angle I9 fixed on each lateral member of the frame immediately below the slit Id. The rule 2 in its way will slide over the angle I9. Superimposed holes are provided into the rabbet of the drafting board I3, the rule 2 and the angle I9, so that a nail dropped into the hole of the rabbet will drop also through the holes of the rule 2 and angle I9, immobilizing the rule bet of the drafting board is designed to receive It can be also suspended by 4 the head of the nail below the level of this rabbet in order not to interfere with the sliding of any T-square which might be used.

The general frame has front and rear members provided with cover plates I5 to protect rollers and web. The lateral members carry the roller ends and the ends of rule 2 in the manner described above. The adjustable device on which bear the axes of the movable roller 4 is mounted also on the lateral members of the frame and consists of a sliding gate II guided on rails I6 fixed on the interior side of the lateral members of the frame. This gate is moved to or away from the rear edge of the board by a bolt I2 fixed to the gate, its other end projecting out from the rear member of the frame. A wing-nut and washer mounted at this end outside of the frame, controls the position of each gate.

The straight-edge rule 1 has its edges beveled and transparent and its end 6 bent downwards close to the lateral members of the frame. At these ends the rule is shaped like a fork so that the ru1es2 ends fit tightly between the two teeth of each fork. Therefore the straight-edge rule I is in the same plane as the rule 2 and being superposed thereabove moves together with the rule 2 and thus determines the movement of the web. Since the nether stretch of the web moves in the same direction as the rules, the upper stretch of the web on the support board moves in the opposite direction, toward the straightedge rule I as shown in Fig. 1. To keep both rules in a perpendicular position to the web, while in movement, sliding shoes II) are mounted to and under both endsof the straight-edge rule I. They slide along the rabbet lateral sides of the board. Of course, it is appreciated that various other constructions may be employed to connect the straight-edge rule I and the rule 2 without departing from the spirit and scope of the present invention.

The entire drafting board as described above performs the movements in both directions in the same manner as shown in Fig. 1 with the res'ults stated therein. It is a drafting board with acontinuous movable drafting area the movement of which is determined, led and controlled by the straight-edge rule. It can be used as a superimposed attachment to any existing drawing table or can be built as an independent drawing table on normal legs or frames.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that such description is not intended in a limiting sense and that certain changes and modifications may be made within the spirit of the invention and'scope of the appended claims.

What is claimed as being new is:

1. In a drafting device, a pair of spaced rollers, an endless web supported on said rollers for movement therearound and having upper and lower stretches intermediate said rollers, and a rule positioned above said upper stretch and connected to said lower stretch for movement with the latter, said rule being movable back and forth between said rollers to effect movement of said upper stretch in a direction opposite to that of said rule.

2. In a drafting device, a pair of parallel spaced rollers, an endless web surrounding and supported on said rollers and adapted to carry on its outer surface a sheet of drawing paper, said web being revoluble aboutsaid rollers and having upper and lower stretches movable in opposite directions, a rule arranged in parallelism with said rollers adjacent to the upper surface of said upper stretch, and means connecting said rule to a portion of said lower stretch for movement with the latter, said rule and upper stretch thus being simultaneously movable in opposite directions to permit rapid positioning of said rule at any selected point on said drawing paper.

3. A drafting device according to claim 2, in combination with a backing plate positioned adjacent to the undersurface of said upper stretch, to provide firm support for drafting operations.

4. A drafting device comprising a frame, a pair of parallel spaced rollers rotatable in said frame,

an endless web surrounding and supported on said rollers and adapted to carry on its outer.

surface a sheet of drawing paper, said web being revoluble about said rollers and having upper and lower stretches movable in opposite directions, a rule arranged in parallelism with said rollers adjacent to the upper surface of said upper stretch, and means connecting said rule to a portion of said lower stretch for movement with the latter, said rule and said upper stretch thus being simultaneously movable in opposite directions to permit rapid positioning of said rule at any selected point on said paper.

5. A drafting device comprising a frame, a pair of parallel spaced rollers rotatable in said frame, an endless web surrounding and supported on said rollers and adapted to carry on its outer surface a sheet of drawing paper, said web being revoluble about said rollers and having upper and lower stretches movable in opposite directions, a 3

rule arranged in parallelism with said rollers ad- J'acent to the upper surface of said upper stretch,

and a bar mounted in said frame for back and forth movement between said rollers, said bar being connected to said rule and said lower stretch. whereby said rule and said upper stretch are movable simultaneously in opposite directions to permit rapid positioning of said rule at any selected point on said paper.

6. In a drafting device including a frame, a pair of parallel spaced rollers rotatable in said frame, an endless web surrounding and supported on said rollers and adapted to carry on its outer surface a sheet of drawing paper, said web being revoluble about said rollers and having upper and lower stretches movable in opposite directions, and a backing plate adjacent to the under surface of said upper stretch, the improvement comprising a bar disposed parallel to and between said rollers and secured to said lower stretch for back and forth movement therewith, and a rule arranged in parallelism with said bar and said rollers adjacent to the upper surface of said upper stretch, said rule being connected to said bar for movement with the latter, so that movement of said rule in one direction serves to move said bar and lower stretch in said one direction and said upper stretch in the opposite direction, whereby said rule may be rapidly positioned at any desired point on said paper and selectively moved to provide complete visual access to said paper.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 534,865 Dolen Feb. 26, 1895 1,896,923 Tevonian Feb. '7, 1933 

